ZR-75-1 cells were fixed with formaldehyde for 10m prior to quenching. Chromatin was prepared and subsequently sheared by the Diagenode BioRuptor Plus for 10 cycles (30 sec on, 30 sec off) on ice. Sheared chromatin was immunoprecipitated with 10µg of AR or ERα antibody, or 2µg H3K27Ac antibody overnight, after coupling to Protein A Dynabeads (10002D). DNA was purified using phenol:chloroform:isoamyl alcohol extraction. Libraries were prepared according to manufacturer's instructions accompanying the Qiagen Ultralow Input Library Kit (Part# 180495). ChIP-Seq; Illumina NextSeq500 (High Output v2) single-end 75 bp reads.